History WMG / BackToTheFuture

Of course, by the end of Part III, and after the obvious passage of many years, his regrets about ever having made the time machine (as of Part II and most of Part III) are allayed. After all, everything worked out fine and he has a happy life with a wife and kids... so he thought, "What the hell!" once more, and made a locomotive time machine...

As we know, she is a fan of Creator/JulesVerne, but the only English-language translations of his books to exist in her time were terrible—so terrible, in fact, that they caused English-speakers to think, for a century, that [[SciFiGhetto only schoolchildren could possibly like them and that they aren’t any good]]. Therefore, Clara must have read the books in French and was able to appreciate them properly.

Marty is an impressionable HardRock loving teenager who sees the documentary, which includes Nigel Tufnel's demonstration of his famous amplifier that goes up to eleven. Marty is suitably impressed; seeking that extra boost for his own music, he looks up someone in Hill Valley who can build equipment for him. And sure enough, Doc is indeed advertising his services in this field (look at the sign outside his garage in 1985). Marty finds Doc, introduces himself, and asks for an amplifier that can go up to eleven like Spın̈al Tap's. Doc sets Marty straight about the problems with his (and Nigel's) thinking, but does so in an informative and entertaining way so that Marty doesn't feel ''that'' stupid. The pair take a shine to each other, and Doc invites Marty to help him build a mega-amplifier anyway -- which Marty sneaks in to test in the very first scene of the film.

Marty is an impressionable HardRock loving teenager who sees the documentary, which includes Nigel Tufnel's demonstration of his famous amplifier that goes UpToEleven. Marty is suitably impressed; seeking that extra boost for his own music, he looks up someone in Hill Valley who can build equipment for him. And sure enough, Doc is indeed advertising his services in this field (look at the sign outside his garage in 1985). Marty finds Doc, introduces himself, and asks for an amplifier that can go up to eleven like Spın̈al Tap's. Doc sets Marty straight about the problems with his (and Nigel's) thinking, but does so in an informative and entertaining way so that Marty doesn't feel ''that'' stupid. The pair take a shine to each other, and Doc invites Marty to help him build a mega-amplifier anyway -- which Marty sneaks in to test in the very first scene of the film.

It's a functionality that's a part of the "Last Time Visited" display. Ordinarily, one would think that it's just a reference allowing you to quickly make a second trip that's the exact reverse of your first trip. But this is more than that; while most time travel takes you to a branching universe, the "Last Time Visited" functionality takes you to the original timeline. So if you used "Last Time Visited" to go to the ''future'', that future will not register anything that you may have changed in the past -- it would genuinely be like you never left!

* The first film is a bit of DramaticIrony for Marty; he's completely unaware that he can just hop in the time machine, hit "Last Time Visited", and go back to his former life (and not the CloseEnoughTimeline he creates) without having to take any action to get his parents back together. The problem is that nobody told him this was possible; Future-Doc got shot before he had a chance to explain it (and was never planning to send Marty to the past anyway), and Past-Doc hasn't built the time machine yet and doesn't know it contains that function. It is kind of a moot point, because (1) Marty still has to wait for the lightning storm to even be able to power the [=DeLorean=] and ''is'' at risk of the DelayedRippleEffect catching up to him while he's still in the past, (2) he actively refuses to use LTV so he can buy himself time to save Future-Doc from getting shot, and (3) he clearly prefers the CloseEnoughTimeline in any event.
* It resolves an inconsistency in what happens when you travel forward in time. The films show different things; in ''Part I'', when Doc sends Einstein one minute forward in time, Einstein never encounters a future version of himself, but when Marty goes forward in time in ''Part II'', we see that there ''is'' a Future-Marty. But one would expect, from Einstein's example, that Marty would have [[GoneToTheFuture gone missing in the future]]. But LTV can explain it. In Einstein's case, with no LTV, he disappears for the length of his minute-long journey. In ''Part II'', Doc had already travelled to 2015 without Marty and encountered a version of Marty who lived out the next thirty years. Not liking what he saw, he went back to 1985 to collect teenaged Marty and then hit LTV so that he would return to the ''exact'' version of 2015 he left -- which contains a Future-Marty (and therefore Marty Jr.). It resolves the problem of how you can "extrapolate" what your future self would have done had you not gone forward in time -- the only way to do this is to travel with someone else by LTV, and that "someone else" would have already seen it.
* Old Biff uses this function to return to 2015. He maybe doesn't understand what he's doing, but it's vitally important. Without LTV, the Ripple Effect would erase him from existence once he arrives in 2015, because he gets killed in the BadFuture's 1996 and he shouldn't exist in 2015 anymore. But with LTV, he doesn't suffer any of the consequences of his trip to the past -- one of which would be no [=DeLorean=]. Without the DelayedRippleEffect (and its inconsistent application), it explains how the [=DeLorean=] doesn't fade out and allows Doc and Marty to leave 2015. (This guess, of course, requires us to disregard the DeletedScene in which Biff fades out once he arrives back in 2015, suggesting the Ripple Effect ''did'' catch up with him. Let's just say that scene was deleted for a reason.)

** The first is a limitation of the LTV protection -- it only works on the people who make the journey. Doc and Marty are inattentive and don't notice that LTV is set to 1955 and not 1985, so they use regular time travel and suddenly encounter Old Biff's changes.
** The second is that LTV [[ItOnlyWorksOnce only works once per timeline]]. It's possible to "undo the undo" -- if you were to LTV and then go back in your original direction, the changes you made would reassert themselves. Perhaps there's a setting that Old Biff unintentionally tripped to cause that to happen.
** The third is that Old Biff figured out how to ''change'' the Last Time Visited. He was only concerned about Doc and Marty finding out that the [=DeLorean=] had been stolen, so he changed LTV to the original 1985 departure date as it was when he stole it. He sees it like rolling back the odometer to obscure a joyride like in ''Film/FerrisBuellersDayOff'', but he somehow managed to shift LTV from 1955 to 1985 ''in the same timeline'', which is as he left it -- with himself in charge. Doc and Marty hit LTV without noticing anything suspicious -- and are in for a nasty surprise when they arrive.
* LTV may also enforce a little SanDimasTime. In the ''Part II'' example, Doc and Marty (and Jennifer) leave 1985 in the morning[[note]]the "What the hell is this?!"/"Breakfast" exchange would have happened only a few minutes earlier[[/note]], but they return to 1985 in the evening. If they used LTV, they should have arrived in the morning. But it works that LTV takes you not to the exact point you left, but rather a certain amount of time later -- the exact amount of time you were gone. And given that they spent most of the day in 2015, they'll have wasted most of the day in 1985. The two trips to 2015 are the only other uses of LTV that we see, and both plausibly run on SanDimasTime -- Old Biff got out of 1955 as soon as he could, and Doc is pretty frantic in 1985 trying to get Marty and Jennifer on the move because if they're too slow, LTV will make him miss his window to intercept Marty Jr. in 2015. If this isn't a requirement of the TimeyWimeyBall, Doc may have included this feature on purpose to prevent awkward questions of aging.

Also, Marty grew up with a father who was interested in science fiction, which possibly rubbed off on Marty to some extent, and gave Marty and Doc a frame of reference for relating to each other.

An interesting theory described in [[http://www.mts.net/~arphaxad/bttf.html this essay]].

* It also wouldn't be necessary to knock out Jennifer for answering too many questions (the Doylist explanation being that the writers simply didn't know what to do with her, hardly an advert for female representation in SF movies...), leaving her to be picked up by police and trapped in her future home.

[[WMG: The ''Back To The Future'' Trilogy is set in the same universe as many other Spielberg/DreamWorks/Amblin productions such as the following....]]

-''Jaws''

-''Jaws 2''

-''Close Encounters Of The Third Kind''

-''E.T.: The Extra-Terrestrial''

-The ''Indiana Jones'' series (all four)

-''An American Tail''

-''The Land Before Time''

-''Who Framed Roger Rabbit''

-''Gremlins'' and ''Gremlins 2: The New Batch''

-''The Goonies''

-The ''Jurassic Park'' Trilogy

-''Mouse Hunt''

-The ''Men In Black'' Trilogy

-''Schindler's List''

-''Saving Private Ryan''

-''The Mask Of Zorro''

-''The Prince Of Egypt''

-''Super 8''

-''Monster House''

-''The Adventures Of Tintin''

-''Munich''

-''The Fabelmans''

* And then he has an argument with Marty over the almanac, claiming it's a misuse of future knowledge, resulting in him angrily and nonchalantly throwing the book in a trashcan, only to be picked up by Biff. If Marty had kept the almanac, he would certainly be less likely to use it for nefarious purposes than Biff ever would. If the Doc had kept the almanac to destroy it safely and properly later, Biff wouldn't get his hands on it. There would then be no need for the alt-1985 and 1955 segments, and the dangerous attempt to wrest the almanac off young Biff in the middle of a thunderstorm wouldn't have left the Doc trapped in 1885.

* Jossed as the company they work for is called [=CusCo=].

* LTV may also enforce a little SanDimasTime. In the ''Part II'' example, Doc and Marty (and Jennifer) leave 1985 in the morning[[note]]the "What the hell is this?!"/"Breakfast" exchange would have happened only a few minutes earlier[[/note]], but they return to 1985 in the evening. If they used LTV, they should have arrived in the morning. But it works that LTV takes you not to the exact point you left, but rather a certain amount of time later -- the exact amount of time you were gone. And given that they spent most of the day in 2015, they'll have wasted most of the day in 1985. The two trips to 2015 are the only other uses of LTV that we see, and both plausibly run on SanDimasTime -- Old Biff got out of 1955 as soon as he could, and Doc is pretty frantic in 1985 trying to get Marty and Jennifer on the move because if they're too slow, LTV will make him miss his window to intercept Marty Jr. in 2015. If this isn't a requirement of the TimeyWimeyBall, Doc may have included this feature on purpose to prevent awkward questions of aging.

* It's never stated but he seems to possess the symptoms of it. He's socially awkward. He is a genius in a particular subject. He is misunderstood by the town. Doc is an undiagnosed Aspie.

* Biff's actions in ''Part 2'' constituted a containment breach, which is why Doc was so adamant about Marty retreiving the Almanac.

** ''Nobody said the entire lab was travelling''. The Doc could have just put a single clock inside the Delorean to test it first, then tested it several more times until every clock was 25 minutes slow, at the exact same time. Think of it as calibration to make sure the machine is actually working properly, after all, how many times have we seen someone travel through time by mistaking one measurement of time for another?

* Confirmed in [[ComicBook/BackToTheFuture the comic book]]. Old Biff mentions having seen ''Film/JurassicPark'', and Doc sees a Music/{{Nirvana}} poster and uses the Internet (Wiki/TheOtherWiki, in fact) during his first visit to 2015.

That's the day Marty and Doc went forward to. Fans everywhere want to compare the writers' predictions to what really happens. Most of them want to see if, contrary to their expectations, [[UsefulNotes/HMTheQueen Queen Elizabeth II]] will be around.

* The refusing to eat sugar could be typical teenager watching his weight, hence why he's drinking [[ProductPlacement Tab]] in 1985 and asks for Pepsi Free in 1955. And in the late 1800s quality dental care was unheard of, so it's meant to be an aversion of EternallyPearlyWhiteTeeth.

*** Seeing that Doc created the system, it's safe to say that the 88 MPH was a setting he made. In the second film, when struck by lightning, the [=DeLorean=] ended up traveling back in time without having to travel to 88 MPH to do so.

*** Seeing that Doc created the system, it's safe to say that the 88 MPH was a setting he made. In the second film, when struck by lightning, the DeLorean ended up traveling back in time without having to travel to 88 MPH to do so.

* The refusing to eat sugar could be typical teenager watching his weight, hence why he's drinking [[ProductPlacement Tab]] in 1985 and asks for Pepsi Free in 1955. And in the late 1800s quality dental care was unheard of.

* His opinion of Marty as an idiot was based more on his behavior that was a result of him being a FishOutOfTemporalWater, which wouldn’t apply when he was growing up in his own time. Plus, in any case, Sam was probably being hyperbolic. Plus, the [=McFly=] family is only seen over the course of a few minutes total in all versions of 1985, where they're first having dinner, then meeting Marty in the morning, and then going out to brunch, so there's no reason why Sam, who doesn't live with them, would appear or come up in conversation outside of Lorraine referencing something (George getting hit by his car) that he was directly involved with.

* His opinion of Marty as an idiot was based more on his behavior that was a result of him being disoriented due to him being a FishOutOfTemporalWater, which wouldn’t apply when he was growing up in his own time. Plus, in any case, Sam was probably being hyperbolic.

* ...not to come off as an ass, but I'm pretty sure Doc wouldn't partake in killing his best friend. Now, the idea that Marty would sell the technology ''is'' feasible, but I think that Doc knows that, considering how Marty essentially screwed over 1985 in "[=BTTF=] Part 2" with the sports almanac, which ended up in Old Biff's hands, Marty wouldn't do anything so stupid. Also, it was asked in Doc's letter from 1885 that when Marty returned back to 1985, he would DESTROY the time machine, and Marty (until it was revealed that Doc DIED in 1885) would honor his friend's wish. But then he had to go back to 1885 to get Doc, and he saw first hand that, thanks to the laws of time travel or some [[WebAnimation/HomestarRunner bull-honkey]], Doc had his chance at love crushed. So, with Doc decided to, out of grief, reinstate his desire to destroy the time machine, Marty would go along with it for his firend's sake. ...[[{{Metaphorgotten}} sorry about that rambling there.]] Bottom line, I don't think Doc would even CONSIDER killing Marty.

That's why she starts off as Claudia Wells in the first movie and has suddenly transformed to Elisabeth Shue by Part II. (Of course it doesn't explain the fact the same scene has played out twice in the subsequent movies with both actresses.)]